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| author | Gregory CLEMENT <gregory.clement@free-electrons.com> | 2013-06-23 13:17:11 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-06-24 17:28:46 +0400 |
| commit | 3e0a07f8c401bb43e0f964c5f1285b2cb2028645 (patch) | |
| tree | 8d25c87e417d999d33f621cf74371df5d6751c66 /arch/arm/mm/proc-v7.S | |
| parent | 63384fd0b1509acf522a8a8fcede09087eedb7df (diff) | |
| download | linux-3e0a07f8c401bb43e0f964c5f1285b2cb2028645.tar.xz | |
ARM: 7773/1: PJ4B: Add support for errata 4742
This commit fixes the regression on Armada 370 (the kernal hang during
boot) introduced by the commit: "ARM: 7691/1: mm: kill unused
TLB_CAN_READ_FROM_L1_CACHE and use ALT_SMP instead".
When coming out of either a Wait for Interrupt (WFI) or a Wait for
Event (WFE) IDLE states, a specific timing sensitivity exists between
the retiring WFI/WFE instructions and the newly issued subsequent
instructions. This sensitivity can result in a CPU hang scenario. The
workaround is to insert either a Data Synchronization Barrier (DSB) or
Data Memory Barrier (DMB) command immediately after the WFI/WFE
instruction.
This commit was based on the work of Lior Amsalem, but heavily
modified to apply the errata fix dynamically according to the
processor type thanks to the suggestions of Russell King and Nicolas
Pitre.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/proc-v7.S')
| -rw-r--r-- | arch/arm/mm/proc-v7.S | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 4c8c9c10a388..e35fec34453e 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -140,6 +140,29 @@ ENTRY(cpu_v7_do_resume) ENDPROC(cpu_v7_do_resume) #endif +#ifdef CONFIG_CPU_PJ4B + globl_equ cpu_pj4b_switch_mm, cpu_v7_switch_mm + globl_equ cpu_pj4b_set_pte_ext, cpu_v7_set_pte_ext + globl_equ cpu_pj4b_proc_init, cpu_v7_proc_init + globl_equ cpu_pj4b_proc_fin, cpu_v7_proc_fin + globl_equ cpu_pj4b_reset, cpu_v7_reset +#ifdef CONFIG_PJ4B_ERRATA_4742 +ENTRY(cpu_pj4b_do_idle) + dsb @ WFI may enter a low-power mode + wfi + dsb @barrier + mov pc, lr +ENDPROC(cpu_pj4b_do_idle) +#else + globl_equ cpu_pj4b_do_idle, cpu_v7_do_idle +#endif + globl_equ cpu_pj4b_dcache_clean_area, cpu_v7_dcache_clean_area + globl_equ cpu_pj4b_do_suspend, cpu_v7_do_suspend + globl_equ cpu_pj4b_do_resume, cpu_v7_do_resume + globl_equ cpu_pj4b_suspend_size, cpu_v7_suspend_size + +#endif + __CPUINIT /* @@ -350,6 +373,9 @@ __v7_setup_stack: @ define struct processor (see <asm/proc-fns.h> and proc-macros.S) define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 +#ifdef CONFIG_CPU_PJ4B + define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 +#endif .section ".rodata" @@ -362,7 +388,7 @@ __v7_setup_stack: /* * Standard v7 proc info content */ -.macro __v7_proc initfunc, mm_mmuflags = 0, io_mmuflags = 0, hwcaps = 0 +.macro __v7_proc initfunc, mm_mmuflags = 0, io_mmuflags = 0, hwcaps = 0, proc_fns = v7_processor_functions ALT_SMP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \ PMD_SECT_AF | PMD_FLAGS_SMP | \mm_mmuflags) ALT_UP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \ @@ -375,7 +401,7 @@ __v7_setup_stack: .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \ HWCAP_EDSP | HWCAP_TLS | \hwcaps .long cpu_v7_name - .long v7_processor_functions + .long \proc_fns .long v7wbi_tlb_fns .long v6_user_fns .long v7_cache_fns @@ -407,12 +433,14 @@ __v7_ca9mp_proc_info: /* * Marvell PJ4B processor. */ +#ifdef CONFIG_CPU_PJ4B .type __v7_pj4b_proc_info, #object __v7_pj4b_proc_info: .long 0x560f5800 .long 0xff0fff00 - __v7_proc __v7_pj4b_setup + __v7_proc __v7_pj4b_setup, proc_fns = pj4b_processor_functions .size __v7_pj4b_proc_info, . - __v7_pj4b_proc_info +#endif /* * ARM Ltd. Cortex A7 processor. |